1. Field of the Invention
The present invention relates to the preparation of hydrargillite, and, more especially, to the preparation of hydrargillite having a high specific surface.
2. Description of the Prior Art
It is known to this art that neutralization of sodium aluminate with an acid results in the formation of amorphous or boehmitic-structure alumina (Kirk-Othmer). The acids which are employed generally and industrially are nitric acid, hydrochloric acid and sulfuric acid.
It too is known that, when hydrofluoric acid is reacted with sodium aluminate, cryolite AlF.sub.3 .multidot.3NaF and/or chiolite AlF.sub.3 .multidot.5/3NaF is/are thus formed.